This invention relates to plastic tubes.
In squeeze tubes, it is common to use a separate closure. However, this requires additional costs incurred in the manufacture of the closure and the equipment for applying the closure.
Among the objectives of the present invention are to provide a one piece blow molded plastic squeeze tube with an integral twist off closure; wherein the tube may be a multilayer tube; wherein the entire package comprising the plastic tube and integral twist off closure tab are blow molded; and wherein the added costs of manufacturing a separate closure and applying a closure are eliminated.
In accordance with the invention, a plastic tube with an integral finish and a twist off tab are blow molded. The twist off tab is connected to the finish of the tube by an annular groove forming a line of weakness. The tab is formed by the closing of mold halves about an extruded parison to form a flat twist off tab connected by a thin membrane to the exterior of the finish. The parison is then blow molded to form the tube. After the mold halves are opened, the twist-off tab is trimmed to provide the finished tube. The tab is formed by a conventional blow molding process without the need of a secondary operation. A plurality of blow molded corrugations are provided between annular blow molded ribs on the finish and provide added strength to the finish to facilitate removal of the tab.